Method and apparatus for sealing the interface of zones having different environmental conditions with an opening in the interface for passing material between the zones

ABSTRACT

Apparatus and method for sealing the interface defining a pair of zones respectively at different environmental conditions, such as pressure, atmospheres or the like, the interface having an opening for passing material, such as a web, strands, etc. between the zones, the seal including an arcuate surface having a facing of low friction material with an opening or openings therein for passing the material therethrough, together with resilient belt means arranged for pressing the material against the facing of low friction material over an extended area thereof in advance of the opening or openings.

United States Patent [191 1111 3,854,222

Lesh et al. 1 1 Dec. 17, 1974 [5 METHOD AND APPARATUS FOR SEALING3,170,576 2/1965 Frank ..,34/242 THE INTERFACE O ZONES HAVING 3,250,0965/ 1966 Nunicki et al 68/5 E CONDITIONS WITH AN OPENING IN THE 3:648:3833/1972 Saundei' sIIL III .1: 34/242 INTERFACE FOR PASSING MATERIALBETWEEN THE ZONES FOREIGN PATENTS OR APPLICATIONS 732,369 4/1966 Canada34/242 Filed: Aug. 10, 1973 Appl. No.: 387,432

US. Cl. 34/15, 34/242, 68/5 E Int. Cl. F26b 5/04 Field of Search 34/15,242; 432/115, 242;

68/5 E; 277/237, DIG. 7

References Cited UNITED STATES PATENTS Sperry 34/242 PrimaryExaminerl(enneth W. Sprague l 57 ABSTRACT Apparatus and method forsealing the interface defining a pair of zones respectively at differentenvironmental conditions, such as pressure, atmospheres or the like, theinterface having an opening for passing material, such as a web,strands, etc. between the zones, the seal including an arcuate surfacehaving a facing of low friction material with an opening or openingstherein for passing the material therethrough, together with resilientbelt means arranged for pressing the material against the facing of lowfriction material over an extended area thereof in advance of theopening or openings.

13 Claims, 4 Drawing Figures PATENTE DEC 1 71974 sum 10F 3 BACKGROUND OFTHE INVENTION Webs and sheets of various materials are frequentlysubjected to pressure conditions different from the ambient pressurecondition. This is usually accomplished by moving the web or sheet intoa chamber having an internal pressure greater or less than the pressureexternally of the chamber. An opening or slot must be formed in a wallportion of the chamber to pass the web or sheet into or out of thechamber. Under conditions of differential pressures on either side ofthe chamber wall opening, seals are provided at the opening for reducingleakage at the opening.

Such known seals take various forms, including the use of a pair ofparallel inflatable tubes with a gap therebetween to define the passagefor the web. The web is passed through the gap between the tubes, whichare then fully inflated to affect a seal, allowing the chamber providedwith such seal to be maintained at desired low or high pressures. Such aseal can only be used in a batch process, since after treatment of theweb, the tubes must be deflated to allow for removal of the threaded weband the introduction of another web for the next cycle.

It has also been suggested to use the inflated tubes forcontinuous'sealing operation. However in such case, the tubes are heldat a single, uniform pressure, but the web must be lubricated or may beof a self lubricatingv character. It will be apparent that the lubricantmay be a contaminant in some cases, which necessarily limits the use ofthis type of seal.

Another form of seal is shown in U.S. Pat. No. 3,l70,576 where multiplerollers in tangential relation are used. However, such construction hasbeen found to show substantial leakage, particularly when used inmultiple stages. Such leakage can give rise to contamination.

Other expedients have been suggested but they have rather limited usesince they are (l very costly; or (2) are of a complex construction.

Accordingly, an object of this invention is to provide an improved sealfor a web treating chamber where the operation may be optionally of thebatch or continuous operation type.

Another object of this invention is to provide a seal which does notrequire lubricants and thus provides for a web treatment which is freeof contaminant lubricants.

A further object of this invention is to provide a seal of the characterdescribed, which is of a construction which materially limits leakage tovery low values and thus avoids the introduction of contaminants intothe sealed chamber.

Yet another object of this invention is to provide a seal assembly whichis of simple construction. readily fabricated, simple to adjust to suitvarying operational conditions, and economical to manufacture.

Other objects of this invention will in part be obvious and in parthereinafter pointed out.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic showing in sideelevation, with parts in section, of a seal assembly embodying theinvention;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a side elevational view, with parts broken away, showing theseal in multi-stage form; and

FIG. 4 is a side elevational view showing the seal applied to a webtreating chamber.

. DESCRIPTION OF THE PREFERRED EMBODIMENTS The instant invention relatesto a seal which is disposed at the interface of two zonesat respectivelydifferent pressures. Thus, the seal may be used in a web treatingchamber, where the web enters or leaves the chamber by way of anelongated slot at a length commensurate with the wide of the web beingtreated; the pressure within the chamber being lower or higher than thepressure externally of the chamber.

The seal comprises essentially a chest arranged on a wall of the chamberfor communication therewith. The chest includes a wall formed with anelongated slot. The wall is on an arcuate shape and formed of a lowfriction material such as nylon or the like. The web or other materialto be treated by introducing the same into the chamber by way of theslot, moves over the arcuate outer surface of the slotted wall and issimultaneously pressed against the low friction surface by a flexiblemember such as an endless resilient belt having a width somewhat greaterthan the width of the web.

Thus, the belt overlaps the web and tightly presses that portion of theweb which is advanced toward the slot; the extent of the web portion sopressed against the low friction surface may be varied by adjusting theposition of the belt mounting assembly toward and away from the lowfriction surface, thereby varying the contact arc of the web withrespect to the low friction surface.

As shown in FIGS. 1, 2 a seal assembly embodying the invention, isgenerally indicated at 10. Such assembly includes a frame 11 having sidemembers 12 and end members 12A, which are held in spaced relation byroller shafts 13, 14 upon which rollers 15, 15' are mountedrespectively. The shaft 13 is mounted in bearings 16 slidably mounted inslots formed in the upper end portions of members 12. The lower roller15' may be coupled by way of its shaft 14 to a drive motor M. An endlessbelt 17 of Neoprene or the like is entrained about rollers 15, 15'.

The frame 11 is mounted on a rectangular flanged member 18 by way ofthreaded members 19 fixed at their inner ends to angle members 19Asecured to the flanged member 18. The outer ends of members 19 areconnected to angle members 193 which are secured to members 12, withlock nuts for fixing the position of the frame 11 relative to member 18.Also mounted on member 18 is a chest 20. Chest 20 comprises a top wall21, a bottom wall 22, end walls 23 and a concavoconvex front wall 24.The chest 20 is open at the rear and the flange portions 25 of member 18are adapted to be fixed to a wall W of a chamber C which is adapted tobe maintained at a pressure P2 by suitable means not shown, which isgreater or less than the pressure of the zone outside of chamber C. Thewall W has an opening 26 to provide for communication between theinterior of chest 20 and the interior of chamber C.

The front wall 24 is formed of a low friction material such as nylon,Teflon, carbon or the like, indicated at 27. The front wall portion 27may be cemented to a backing sheet 28 of metal or the like. The portion27 and sheet 28 are formed with registering elongated slots 27'; 28'.

A reel 29 of fabric or the like, which is to be treated within chamber Cat the pressure therein has its web 30 fed between belt 17 and the lowfriction wall portion 27 and passed through slots 27', 28 into chest 20and thence into chamber C. The belt 17 has a width somewhat greater thanthe length of registering slots 27, 28 so that its lateral marginalportions can overlap the side edges of web 30.

The web 30 is moved by the belt 17 which is driven by motor M, intochamber C. Alternatively, the web 30 may be pulled by rollers 31, 32which are driven by suitable motor means, now shown, located outside ofchest 20 and having a conventional shaft seal, not shown.

It will be apparent that the web 30 is tightly pressed against the lowfriction surface 27 while the same is moving through the slots 27', 28,to thereby provide an effective seal between the zones P1 and P2 ofdifferential pressures.

The tension of belt 17 may be adjusted by adjusting slidable bearings 16and thereby vary the position of roller shaft 13 with respect to rollershaft 14. Also, the assembly including rollers 15, 15 and belt 17 andmotor M may be moved toward and away from chest by positioning screws 19and locating nuts on the outer ends thereof thus varying the arcuateextent of belt 17 which is in sealing relation to low friction surface27.

When the difference between the pressures of zones P1, P2, issubstantial, multiple seals may be used in series as shown in FIG. 3.Here, a second chest 20A, is mounted on chest 20, in communicatingrelation to each other. Chest 20A, includes all the elements of chest20, including belt 17A, rollers 15A, 15A, low

friction surface 27A; and pull rollers 31A, 32A.

Thus, the web 30 first passes over low friction surface 27 of chest 20and into said chest 20 by way of slots 27, 28; belt 17 pressing themoving web 30 against convex low friction surface 27. The web 30 thenpasses from chest 20 to chest 20A which is enclosed in a rectangularframe 40 comprising a top wall 41, bottom wall 42 and side walls 43, andperipheral flanges 44, 45 which abut flange 18 and chamber wall Wrespectively. The web 30 then passes over low friction surface 27A ofchest 20A, with pressure by belt 17A and thence by way of slots 27 'Aand 28'A into chamber C.

It is noted that chests 20, 20A allow for successively differentpressure zones P1, P2 and P3. Suitable vacuum or pressure pumps, notshown, provide the stepped pressures P2, P3 relative to an ambientpressure P1.

lt web 30 is to leave chamber C after suitable treatment thereof withinthe chamber; similar seals may be applied to the exit side of saidchamber C.

In FIG. 4, there is shown the apparatus of the instant invention whereinthe operation is of the batch type. 6

a bottom wall 57, side walls 58, together with a concavoconvex frontwall 59 formed of a curved nylon sheet. A transversely extending slot 60in wall 59 allows for entry of web 61 into chest 55 and thence intochamber C.

- Theweb 61 is pressed against the convex surface of low friction wall59 in advance of slot 60, by belt 62 entrained over rollers 63, 64, andsuitably tensioned thereon. Belt 62 is driven by motor M connected bychain 65 to roller 64 by way of a sprocket wheel 66.

The chest 55 includes a peripheral flange portion 67 which abuts and issecured to a flange portion 68 of chamber front wall 52. The web 61 thuspasses from chest55 to chamber C which is maintained at a suitablepressure different from the ambient pressure by pumps, not shown.

The web 61 is positively advanced within chamber C by pull rollers 69,70; where roller 70 is driven by way of a motor 71, sprocket wheel 71A,chain 72, sprocket wheel 73 and a shaft 74 mounted in a rotary seal 75on chamber wall 53. A bevel gear 76 on the inner end of shaft 74, mesheswith a second bevel gear 77 which in turn rotates a sprocket wheel 78connected to a sprocket wheel 79 on roller 70 by way of a chain 80.

The web 61 is thus moved onto a guide plate 81 in gathered form. lt isunderstood that web 61 is subjected to the selected pressure withinchamber C in connection with vacuum impregnating operations, etc. Insuch operation, it has been found that leakage has been substantiallyreduced, thereby reducing operational costs to maintain a given pressuredifferential. Further, webs of varying widths up to the length of theslot in the chests, may be subjected to the desired treatment.

within the chamber.

It is understood that the material being treated may be moving betweenzones of varying environments, including vapor, steam, various gases,which may be at differential pressures and/or temperatures.

Further, the material being treated in accordance with the instantinvention may be in the fonn of strands, yarns and the like as well asin sheet or web form. a

We claim:

1. Apparatus for subjecting material to successive environmentalconditions comprising a chamber maintained internally thereof at anenvironmental condition different from the environmental conditionexternally thereof, said chamber including a wall portion formed with anopening therein for passing said material therethrough, said wallportion being arcuate to provide a convex outer surface, means forsealing the opening in said wall portion, said sealing means comprisinga flexible member for overlying and pressing said material against theconvex surface portion of said wall portion, and means for tightlyconforming said flexible member to said convex surface along areas ofsaid convex surface extending from opposite sides of said opening.

2. Apparatus as in claim 1 wherein said convex surface of said wallportion includes an exposed face of low friction material.

3. Apparatus as in claim 1 wherein said flexible member comprises anendless resilient belt, said material being disposed between an innerrun portion of said belt and the outer surface of said layer of lowfriction material.

4. Apparatus as in claim 3 and further including means for varying theeffective arcuate extent of said belt run portion.

5. Apparatus as in claim 3, and further including a pair of spacedrollers, said endless belt being mounted on said rollers, and means foradjustably moving one of said rollers relative to the other roller.

6. Apparatus as in claim 5, and further including means for moving saidrollers towards and away from said layer of low friction material toadjust the arcuate extent of the inner run portion of said belt.

7. Apparatus as in claim 6 and further including means for driving oneof said rollers.

8. Apparatus as in claim 6 and further including means within saidchamber for moving said material through said registering openings.

9. Apparatus as in claim 1, and further including second seal meansmounted on said first mentioned seal means and in communicating relationthereto, whereby said web may pass through the successive seal means andsaid chamber.

10. Apparatus as in claim 1, wherein said low friction material isnylon.

' 11. A method of subjecting material to successive differentenvironmental conditions comprising passing said material between zonesof different environmental conditions, the interface of said zones beingdefined by a separating wall having a convex surface and a facing of lowfriction material on said convex surface, said wall having an openingtherein, moving said material over the facing of low friction materialand through said opening and resiliently pressing the moving materialagainst said facing of low friction material.

12. A method as in claim 11, wherein said successive environmentalconditions are at different pressures.

13. A method as in claim 12 wherein said material is a fabric web.

I UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. D t dl7,

Inventor) Robert M. Lesh et 9.1.

' It 1s c ertifled that error appears 1n the above-ldentlfled patent andthat said Letters Patent are hereby corrected as shown below:

In item [76] "Eugene T. Woodberry, Jr. should read Eugene TLWoodbery,Jr.

Signed and sealed this 18th day of February 1975.

(SEAL) Attest:

I I C. MARSHALL DANN' RUTH C. MASON Commissioner of Patents AttestingOfficer and Trademarks USCOMM'DC 60376-P69 FORM Po-1os0 (10.69)

UIS. GOVERNMENT PRINTING OFFICE: 59, 93 o sun-arm v .7

1. Apparatus for subjecting material to successive environmentalconditions comprising a chamber maintained internally thereof at anenvironmental condition different from the environmental conditionexternally thereof, said chamber including a wall portion formed with anopening therein for passing said material therethrough, said wallportion being arcuate to provide a convex outer surface, means forsealing the opening in said wall portion, said sealing means comprisinga flexible member for overlying and pressing said material against theconvex surface portion of said wall portion, and means for tightlyconforming said flexible member to said convex surface along areas ofsaid convex surface extending from opposite sides of said opening. 2.Apparatus as in claim 1 wherein said convex surface of said wall portionincludes an exposed face of low friction material.
 3. Apparatus as inclaim 1 wherein said flexible member comprises an endless resilientbelt, said material being disposed between an inner run portion of saidbelt and the outer surface of said layer of low friction material. 4.Apparatus as in claim 3 and further including means for varying theeffective arcuate extent of said belt run portion.
 5. Apparatus as inclaim 3, and further including a pair of spaced rollers, said endlessbelt being mounted on said rollers, and means for adjustably moving oneof said rollers relative to the other roller.
 6. Apparatus as in claim5, and further including means for moving said rollers towards and awayfrom said layer of low friction material to adjust the arcuate extent ofthe inner run portion of said belt.
 7. Apparatus as in claim 6 andfurther including means for driving one of said rollers.
 8. Apparatus asin claim 6 and further including means within said chamber for movingsaid material through said registering openings.
 9. Apparatus as inclaim 1, and further including second seal means mounted on said firstmentioned seal means and in communicating relation thereto, whereby saidweb may pass through the successive seal means and said chamber. 10.Apparatus as in claim 1, wherein said low friction material is nylon.11. A method of subjecting material to successive differentenvironmental conditions comprising passing said material between zonesof different environmental conditions, the interface of said zones beingdefined by a separating wall having a convex surface and a facing of lowfriction material on said convex surface, said wall having an openingtherein, moving said material over the facing of low friction materialand through said opening and resiliently pressing the moving materialagainst said facing of low friction material.
 12. A method as in claim11, wherein said successive environmental conditions are at differentpressures.
 13. A method as in claim 12 wherein said material is a fabricweb.